(i) Field of the Invention
The present invention relates to a fire alarm pull station. In particular, the present invention relates to a fire alarm pull station enclosure which comprises a rectangular metal box having an open front in which a breakable pane of glass is supported.
(ii) Description of the Related Art
It is well known in the art of fire alarm safety devices to use breakable glass fronts in order to gain access to either fire extinguishers, fire hoses or fire alarm pull levers. Generally, there are two types of fire alarm pull stations on which all variations are based. The first "free lever" pull type employs a small glass rod of minimal diameter or a small pane of glass which is shattered upon pull lever activation. The pull lever is not enclosed by a pull station "box". Edwards U.S. Pat. No. 2,083,324 issued Jun. 8, 1937 discloses such a fire alarm pull station in which an exposed pull lever contains a small pane of glass which is shattered upon activation of the pull lever in a downward fashion. The pane of glass only protects actuation of circuitry and does not prevent tampering with the lever.
The second "box enclosure" type has a pull lever enclosed within a rectangular or square box with a breakable glass front. The disadvantages of the free lever type of pull station, namely possible tampering with the pull lever due to unimpeded access, have been substantially overcome by the use of the enclosed pull station. Once the glass front is shattered one gains access to the pull lever. However, there have also been significant disadvantages to the box type pull stations. The first is the impeded access to the lever itself. While this structure was introduced to alleviate concerns with the free lever type pull station, the encasement of the lever, while eliminating some problems, has also created others. One must break the outer pane of glass to actuate the lever located inside the box. At times several blows to the glass pane are required to remove the outer glass and gain access to the lever. This results in lost time which is vitally important to the operator. The second disadvantage to the box type pull station is the safety issue regarding glass fragments remaining attached to the outer metal box. The conventional embodiment of the box type pull station has grooves which surround the pane and provide the pane of glass with stability. Once the pane is shattered, several glass fragments can remain within these grooves and provide a significant safety risk to the user when the user attempts to activate the pull lever. This risk is magnified in that the operator of the device, having discovered a fire, will invariably be under stress and will try to operate the device as quickly as possible. It is a principal object of the present invention to improve upon the latter "box enclosure" fire alarm pull station.